Substrate processing apparatuses have been conventionally used to perform various types of processes on substrates such as semiconductor wafers, glass substrates for photomasks, glass substrates for liquid crystal displays, glass substrates for optical disks or the like.
For example, the substrate processing apparatus including a reversing unit that reverses a top surface and a back surface of the substrate is described in JP 2004-146708 A. In such a substrate processing apparatus, a center robot (transport unit) that transports the substrate is arranged in substantially the center of a processing section having a rectangular shape.
In the processing section, a plurality of (four, for example) back surface cleaning units that perform cleaning processes on the back surfaces of the substrates, respectively, are arranged so as to surround the center robot. In addition, are arranged so as to surround the center robot. In addition, the reversing unit is arranged in a position where the center robot can access in the processing section.
An indexer section including a plurality of storing containers that store the substrates is provided on one end of the processing section. A substrate transport robot that takes the substrate before processing out of the above-mentioned storing container or stores the substrate after the processing in the above-mentioned storing container is provided in this indexer section.
In the above-described configuration, the substrate transport robot takes the substrate before the processing out of any of the storing containers and transfers it to the center robot while receiving the substrate after the processing from the center robot and storing it in the storing container.
The center robot receives the substrate before the processing from the substrate transport robot and subsequently transfers the received substrate to the reversing unit. The reversing unit reverses the substrate received from the center robot so that the top surface thereof is directed downward. Then, the center robot receives the substrate reversed by the reversing unit and carries the substrate to any of the back surface cleaning units.
Next, when the processing is finished in any of the back surface cleaning units described above, the center robot carries the substrate out of the back surface cleaning unit and again transfers it to the reversing unit. The reversing unit reverses the substrate that has been subjected to the processing in the back surface cleaning unit so that the top surface thereof is directed upward.
The center robot subsequently receives the substrate reversed by the reversing unit and transfers it to the substrate transport robot. The substrate transport robot receives the substrate after the processing from the center robot and stores it in the storing container.
As described above, the substrate before the processing stored in the storing container is reversed by the reversing unit and subjected to the processing (processing to the back surface of the substrate) in the back surface cleaning unit, and subsequently reversed again by the reversing unit and stored in the storing container as the substrate after the processing.
However, many transporting processes are performed by the center robot in the configuration of the conventional substrate processing apparatus described above. Specifically, the center robot is required to perform four transporting processes for the single substrate, that is, a transporting process from the substrate transport robot to the reversing unit, a transporting process from the reversing unit to the back surface cleaning unit, a transporting process from the back surface cleaning unit to the reversing unit and a transporting process from the reversing unit to the substrate transport robot.
Many transporting processes by the center robot among the substrate transport robot, the reversing unit and the plurality of back surface cleaning units described above reduce the throughput of the substrate processing.
Moreover, when cleaning processing of the back surface of the substrate and cleaning processing of the top surface of the substrate are performed in the substrate processing apparatus, a plurality of top surface cleaning units are arranged in the processing section instead of part of the back surface cleaning units.
In such a configuration, the center robot is required to perform five transporting processes for the single substrate, that is, the transporting process from the substrate transport robot to the reversing unit, the transporting process from the reversing unit to the back surface cleaning unit, the transporting process from the back surface cleaning unit to the reversing unit, a transporting process from the reversing unit to the top surface cleaning unit and a transporting process from the top surface cleaning unit to the substrate transport robot.
Also in this case, many transporting processes by the center robot among the substrate transport robot, the reversing unit, the plurality of back surface cleaning units and the plurality of top surface cleaning units reduce the throughput of the substrate processing.